I have a PCI-6221 connected to a SC-2345 (white with back connection). I also have a SCC-SG01 and a SCC-TC02 module. I’ve connected a strain gage to the SG01 module and a K-type thermocouple to the TC02 module. My strain gage is connected to Vex and ACH of the SG01 module while the ACH and R channels are shorted with a small wire (per SG01 manual). I can see a nice dynamic signal out of the SG01 module when I bend the strain gage, so I know my gage measurement is working fine.
Things turn ugly when I plug in the TC02 module and try to read a temperature along with my strain measurement. As long as the SG01 module is plugged in, the TC02 module reads a completely wrong temperature (My lab is not set at 190 deg C!) with a lot of noise (temperature reading jumps between 170 and 190 C). But as soon as I physically take the SG01 module off the SC2345, the temperature reading comes back to a more realistic level (25 C) and becomes very stable.
My thermocouple’s red wire is connected to TC02’s TC(-) and the yellow wire is connected to TC02’s TC(+). SG01 is plugged into analog input channel 2/10 while TC02 is plugged into analog input channel 4/12 while. Both the strain gage and the thermocouple are physically separated by a few inches (no common connection that I can see). I’ve tried changing channels for the TC02 module without any improvement.
Can someone please help me figure out why I can’t measure strain and temperature at the same time? Thanks.